Canadian Forest Service Publications

Reduced vulnerability to hyperparasitism in nondiapause strains of Cotesia melanoscela (Ratzeburg) (Hymenoptera: Braconidae) 1995. Nealis, V.G.; Bourchier, R.S. Proceedings of the Entomological Society of Ontario 126: 29-35.

Year: 1995

Available from: Great Lakes Forestry Centre

Catalog ID: 21560

Language: English

CFS Availability: PDF (request by e-mail)

Abstract

The vulnerability to predation and hyperparasitism of an introduced European strain of Cotesia melanoscela (Ratzeburg) (Hymenoptera: Braconidae) and an Asian strain of the parasitoid with a different cocoon morphology and no diapause state was compared in southern Ontario, Canada. The rates of predation and hyperparasitism were not related to cocoon morphology but were dependent on the length of time that cocoons were exposed to hyperparasitism in the field. The nondiapause characteristic of the Asian strain decreases its exposure time and hence reduces its vulnerability to hyperparasitism. Inundative release programs involving Cotesia spp. will be more effective using nondiapause strains of this parasitoid and by making releases as early as possible in the season to minimize their exposure to hyperparasitoids.

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